1. Field of the Invention
The present invention relates generally to the field of insulating support columns for driving interrupting units of high voltage circuit protection arrangements and more particularly to an improved insulating support column including a translational operating member that extends axially through and outside of both ends of the insulating support column.
2. Description of the Related Art
Various drive linkage arrangements are known for high-voltage circuit breakers and for high-voltage interrupting units. One category of drive linkage arrangement include insulating columns with pressurized gas or oil that carry translational operating members that are driven in various manners; commonly by pivotal linkage members that enter the sealed, insulated column through an "O" ring seal or the like. Other types of drive linkage arrangements in this category can be described as using a crank with a rotary shaft seal; for example as shown in Sprecher & Schuh publications 42F1 entitled "HGF 100 SF.sub.6 Outdoor Circuit Breaker Series", 41F5 entitled "HP506-A New Efficient Circuit Breaker for Distribution Switchgear", 4120 entitled "Low Oil Content Circuit Breaker for 52 . . . 72.5 kV Indoor Installation" (October 1975), 4150 entitled "Low Oil Content Circuit Breaker for Outdoor Stations 10 . . . 82.5 kV" (December 1977), and Sprecher News, March 1980. Another type of drive linkage arrangement in this category utilizes a pneumatically- or mechanically-driven operating rod that extends into a pressurized column; seals being provided between the translational operating rod and the pressurized column. Arrangements of this type are shown in ASEA Pamphlet LA36-102E entitled "SF.sub.6 Circuit-Breaker Type HPL", AEG brochure entitled "SF.sub.6 Circuit-Breaker for Rated Voltages of 72.5 kV up to 765 kV", and BBC Brown, Boveri & Company Publication No. CH-A083 322 E entitled "SF.sub.6 Circuit-Breaker Type ELF and Type ELI".
Another drive linkage arrangement described in U.S. Pat. No. 3,566,055 and IEEE paper C 74 170-7 provides for rotation of an insulator 31 (FIGS. 3 and 4) to operate a T-shaped movable switch component 30. The drive linkage arrangement also provides for rotation of an insulated rotary shaft 51 (FIGS. 5 and 8-11) that extends upwardly through the insulator 31 into the center section 33. The rotation of the insulated shaft 51 operates mechansims that in turn operate the interrupting device 40 and a bypass device 44. The shaft 51 and the insulator 31 are rotated in timed relationship. Neither the dielectric withstand capability nor the insulating properties of the insulator 31 are addressed. Although the shaft 51 is referred to as an insulated shaft, the shaft 51 is apparently metallic and no provisions are disclosed for dielectric consideration of the overall movable switch component 30 and no seals are disclosed between the insulator 31 and the shaft 51.
While these arrangements may be generally suitable for their intended purposes, none of these arrangements provides translational movement of an operating member that extends out the top of an insulating support column, that is driven below the insulating support column, and that includes metallic end portions.